联合麻醉术中知晓与脑电双频指数关系的分析

目的　探讨硬膜外阻滞复合全身麻醉术中知晓的发生率以及脑电双频指数 (BIS)与镇静深度的关系。方法　选择ASAⅠ～Ⅱ级的肝癌手术患者 2 40例 ,麻醉方法均为硬膜外阻滞加全麻。分为两组 :异丙酚组 (P组 ,n =12 0 ) ,术前 30分钟肌注苯巴比妥钠 0 1g、阿托品 0 3mg ,诱导用芬太尼 4μg/kg、异丙酚 1 5mg/kg、琥珀胆碱 2mg/kg ,维持用异丙酚 12mg·kg-1·h-1,持续 15分钟后改为 3mg·kg-1·h-1至术毕 ;硫喷妥钠组 (T组 ,n =12 0 ) ,术前 30分钟肌注咪唑安定 0 0 75～ 0 1mg/kg、阿托品 0 3mg ,诱导用硫喷妥钠 6mg/kg替换P组的异丙酚 ,其余药相同 ,维持用 6 0 %的N2 O吸入至术毕。两组均在诱导前 15分钟开始在硬膜外导管内注入 0 5 %布比卡因 4ml。术中持续监测BIS和边缘频率 (SEF)。结果　诱导前两组患者的EEG无差异 ;诱导后 15分钟和 30分钟 ,EEG抑制 ,BIS和SEF均降低 ,组间无差异 ;诱导后 6 0分钟和 12 0分钟 ,P组的BIS和SEF比T组低 (P <0 0 5 )。P组 1例术中知晓。结论　联合麻醉中 ,用BIS监测预防术中知晓的发生缺乏精确性。

The relationship between the awareness in combined epidural-general anesthesia and the bispectral index,spectral edge frequence of electroencephalogram

Objective To study the relationship between the awareness incombined epidural-general anesthesia and the bispectral index，spectral edge frequency of electroencephalogram．Methods 240 liver cancer patients were randomly divided into propofol （group P，n＝120）and thiopentone （group T，n＝120） groups．In group P，anesthesia was induced with propofol 1.5mg／kg and maintained with propofol 12mg.kg－1.h－1for 15 minutes and 3mg.kg－1.h－1 thereafter．In group T，thiopentone 6mg／kg was used to facilitate the induction and 60％ N2O was inhaled to maintaine the anesthesia．All patients received epidural block during operations．The BIS was continuously monitored with computerized power spectral analysis device．Results There were no differences in BIS between two groups before induction．At 15 and 30 min after intubation， EEG was depressed slightly in both groups．Although BIS and SEF （60min and 120min after intubation）were lower in group P，one awareness happened during operation in P group．Conclusions Monitoring the BIS could not reliably prevent the happening of the awareness during operation in combined epidural-general anesthesia．